Sodium hydrogen N-(1-oxododecyl)-L-glutamate

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 21, January 2021 to 25, February 2021

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 310 (Ready Biodegradability - CO2 in Sealed Vessels (Headspace Test)

Version / remarks:

2014

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Quality Assesment is on page 4 of the attched report

Specific details on test material used for the study:

Batch no.: y191119 supplied by the sponsor
Aspect: white powder
Purity: 97.3%
Solubility: soluble in water
Storage condition of test material: room temperature (15 °C - 25 °C), stable for at least 20 months
Stability and homogeneity of the test material in the vehicle/solvent under test conditions (e.g. in the exposure medium): stable for 12 months minimum
Solubility: soluble and stable in water
Reactivity of the test material with the incubation material used (e.g. plastic ware): not reactive
pH (sol. 5% 20 °C) = 5.10
More information can be found on the attached report

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, predominantly domestic, non-adapted

Details on inoculum:

For the inoculum preparation a sample of aerobic sludge has been selected by the mixed treatment plant of urban (about 66%) and industrial (about 34%) liquid sewage situated at San Rocco - Monza (MI), Italy. The plant of treatment is managed by "BRIANZACQUE SRL (Monza)".
In the laboratory the sampled muds have been mixed and let settle, keeping them in aerobic conditions. The mud samples, before their use, have been analysed to check thier ability to form colony units. Then it has been centrifuged, washed and analyzed to quantify the suspended solid concentration for the inoculum.
The inoculum has been prepared in order to have a concentration of suspended solid of 4 mg/l.
The inoculum has not pre-adapted to the test item.
The inoculum has given, at the beginning of the test, 4.2 10exp2 cfu/ml in test vessel.

Duration of test (contact time):

28 d

Initial conc.:

20.23 mg/L

Based on:

TOC

Parameter followed for biodegradation estimation:

inorg. C analysis

Remarks:

TIC was evaluated

Details on study design:

The follwowin solutions in demi water have been prepared:
Solution A: KH2PO4 anhydrous 8.50 g/l, K2HPO4 anhydrous 21.75 g/l, Na2HPO4 2H2O 33.40 g/l, NH4Cl 0.50g/l
Solution B: CaCl2 2H2O 36.40 g/l
Solution C: MgS04 7H2O 22.50 g/l
Solution D: FeCl3 6H2O 0.25 g/l
Then for each liter of medium 10 ml of solution A have been transferredinto a 1000 ml volumetric flask and diluted with 800 ml of deionized water; 1ml of solution B, C and D have been added and the solution has been brought to volume.
Bottles preparation:
Bottles have been used as follows adding the muds in each bottles except bottles for abiotic check.
Blank, 23 replica, 17 used, 3 replications once a week and 5 replications on 28th day.
Test sample, 23 replica, 17 used, 3 replications once a week and 5 replications on 28th day.
Reference substance, 23 replica, 17 used, 3 replications once a week and 5 replications on 28th day.
Test sample + Reference substance, 8 replica, 8 used, 3 replications firts day and 5 replications on 28th day.
Abiotic check, 8 replica, 8 used, 3 replications firts day and 5 replications on 28th day (the item has put together with 50 mg/l of HgCl2 to check possible abiotic degradation.
The inoculum has been addedin all bottles, closed and incubation continued under stirring in darkness at 20 +/- 1 °C for 28 days. Data recording is performed continuously by a validated informatic monitoring system (Labguard Evisense).
At least 1 hour before every determination of inorganic carbon (TIC) the reaction in one bottle of blank, one of reference substance and one of the test item has been stopped with the addition of 6 mL of sodium hydroxide (1 M). Triplicate bottles have been analyzed to detect inorganic carbon (IC) at each check point, weekly, except at the end of the test where five bottles have been analyzed.

Reference substance:

benzoic acid, sodium salt

Remarks:

Sigma Aldrich, batch SLBW2610, TOC 20.11mg/l

Key result

Parameter:

% degradation (inorg. C analysis)

Value:

89

Sampling time:

28 d

Remarks on result:

other: Value subtracted by the abiotic degradation

Key result

Parameter:

% degradation (inorg. C analysis)

Value:

93

Sampling time:

28 d

Remarks on result:

other: At the end of the test

Details on results:

EXPRESSIONS OF RESULTS
Total biodegradation (Dt) has been calculated using the equation:
Dt = [(TICt - TICb)/TOCi ] x100
where TICt is the concentration of inorganic carbon, in mg, produced by biodegradation of test item, TICb is the concentration of inorganic carbon, in mg, produced by biodegradation in blank TOCi is the concentration of organic carbon of the test substance, in mg, added at the beginning.
The value of of inorganic carbon is the highest recorded during 28 days of experimental period.
INTERPRETATION OF RESULTS
The test is considered valid when:
- the percentage of average degradation of the reference substance is more than 60%after 14 days of incubation.
- the mean amount of TIC present in the blank at the end of the test is < 3 mg C/L
- the difference of extremes of replicate values of the test item at the plateau, at the end of the test or, if appropriate, at the end of the 10-d window should be <= 20%
A substance is considered readily biodegradable when its level of biodegradability is at least 60%,
within 10d window during the test.
If, at day 28, the biodegradation in the bottle contained both the test sample and the reference substance referred to biodegradation in the bottle with reference substance results < 25%, it may be assumed that the test substance doesn’t inhibited the activity of the inoculum.
RESULTS
Validity criteria of the test are satisfied (see data below and table 2 of the attached report).
Test item is considered readily biodegradable because its biodegradability has been higher than 60%, within a 10d window during the test.
The mean amount of TIC present in the blank controls at the end of the test is < 3 mg C/L (see
attachment N. 3 of the attached report).
Abiotic degradation occurred because amount of TIC during the test in the abiotic bottles has been higher than 10%(see below).
TIC T = 1 day average ppm =3.215
TIC T = 28 day average ppm =3.638
% Increase (<10%) = 13.7%.
The biodegradation percentage of the test item during the test is detailed in attachment N. 3 of the attached report and summarized in the table below.
The trend of inorganic carbon and related biodegradation percentages in the bottle contained test sample and reference substance confirms the absence of any inhibitor effect of the test sample on inoculum at the concentration at which it was applied in the test (4.12%).
Graphics and tables are on the attached report.

Results with reference substance:

See table below in any other information on results

Check point (days)

% Biodegradation Reference substance

% Biodegradation Test item

% Biodegradation Test item + reference substance

0	0	0	0
1	24	0	31
2	68	35	-
12	85	88	-
21	101	108	-
28	97	92	93

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

According to OECD 310:2014 the test item Sodium hydrogen N-(1-oxododecyl)-L-glutamate is readily biodegradable (93% and 89% if result is subtracted by abiotic degradation )

Executive summary:

On the test item, “SODIUM HYDROGEN N-(1-OXODODECYL)-L-GLUTAMATE”, the analysis of inorganic carbon for the evaluation in an aqueous medium of the aerobic biodegradability has been performed following screening method described in OECD 310: 2014. For this purpose, the amount of developed inorganic carbon has been measured and reported in comparison to the blank. The test has been done using the test item with a fixed concentration of organic carbon.  Samples have been kept at the temperature of 20 +/- 1 °C for the whole period of the test (28 days).On the basis of results obtained, interpreted in accordance to OECD 310:2014, the test item “SODIUMHYDROGEN N-(1-OXODODECYL)-L-GLUTAMATE”is considered readily biodegradable in aerobic conditions.

Description of key information

According to OECD 310:2014 the test item Sodium hydrogen N-(1-oxododecyl)-L-glutamate is readily biodegradable (93% and 89% if result is subtracted by abiotic degradation )

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater

Additional information

On the test item, “SODIUM HYDROGEN N-(1-OXODODECYL)-L-GLUTAMATE”, the analysis of inorganic carbon for the evaluation in an aqueous medium of the aerobic biodegradability has been performed following screening method described in OECD 310: 2014. For this purpose, the amount of developed inorganic carbon has been measured and reported in comparison to the blank. The test has been done using the test item with a fixed concentration of organic carbon.  Samples have been kept at the temperature of 20 +/- 1 °C for the whole period of the test (28 days).On the basis of results obtained, interpreted in accordance to OECD 310:2014, the test item “SODIUMHYDROGEN N-(1-OXODODECYL)-L-GLUTAMATE” is considered readily biodegradable in aerobic conditions.